Abstract: Carbon fiber reinforced plastic is a new high-quality lightweight material in recent years. It has good mechanical properties and is widely used in the automotive, electronics and other industries. Short carbon fiber reinforced plastics are usually injection molded and their properties are closely related to fiber distribution. In order to deepen the understanding of the internal fiber distribution of staple fiber carbon fiber reinforced plastics, SEM and X-ray tomography tests were carried out. The fiber extraction hole diameter, the projected length of the flow plane fiber and the distribution of fiber orientation were obtained by image processing technology, and the law of fiber orientation distribution was further verified by comparison with the Moldex simulation results. The results show that the fiber extraction hole diameter distribution of carbon fiber reinforced plastics is not affected by the fiber content. The overall orientation of fiber orientation is the flow direction, and the orientation probability along the flow direction increases first and then decreases with the decrease of the distance from the plane to the core layer. In the case of carbon fiber reinforced plastic injection molding, the areas with a higher orientation ratio in the flow direction are located in the middle of the skin layer and the core layer.

Key words: carbon fiber reinforced plastics, fiber distribution, flow direction, characterization